Naming of chip resistors 2

The allowable error between the reading and the nominal resistance is ±5%, ±10%, or ±20% respectively. If there is a discrepancy and the value exceeds the error range, it indicates that the resistance value has changed. B. Note: When testing, especially when measuring resistors with values above tens of kΩ, avoid touching the probe and the conductive parts of the resistor with your hands; the resistor being tested should be soldered off from the circuit, with at least one end disconnected, to prevent other components in the circuit from affecting the test and causing measurement errors; although the resistance value of a color-ring resistor can be determined by the color ring markings, it is best to use a multimeter to test its actual resistance when in use. 2. Detection of cement resistors The method and precautions for detecting cement resistors are exactly the same as those for detecting ordinary fixed resistors.  3.  In the circuit, when the fuse resistor is fused and open-circuited, one can make a judgment based on experience: if the surface of the fuse resistor is found to be blackened or burnt, it can be concluded that its load is too heavy, and the current passing through it is many times higher than the rated value; if there are no traces on its surface and it is open-circuited, it indicates that the current flowing through it is just equal to or slightly greater than its rated fusing value. To judge the quality of a fuse resistor with no traces on its surface, one can use a multimeter set to R×1 range. To ensure accurate measurement, one end of the fuse resistor should be soldered off from the circuit. If the measured.diode resistance is infinite, it indicates that the fuse resistor has failed and is open-circuited. If the measured resistance differs greatly from the nominal value, it indicates that the resistance has changed and should not be used anymore. In maintenance practice, it has been found that a small number of fuse resistors are also punctured and short-circuited in the circuit, which should also be noted during inspection. 4. Inspection of Potentiometers When inspecting a potentiometer, first rotate the knob to see if it turns smoothly, if the switch is flexible, and if the "click" sound when the switch is turned on and off is crisp. Also listen to the sound of friction between the internal contact points and the resistor body of the potentiometer. If there is a "rustling" sound, it indicates poor quality.diode